I Love Lisa - S4-E15
Other mistake: When Lisa and Ralph are swinging at the end, they are swinging outside the frame, but the swing is tied at the top of the inside of the frame.
Homer's Barbershop Quartet - S5-E1
Other mistake: When Bart and Lisa are looking at records, there is a picture of Homer. He had hair at the time the record was made, and the hat he's wearing isn't big enough to cover it, but there's none visible as there should be.
Tree House of Horror II: A Simpsons Halloween - S3-E7
Other mistake: As Mr. Burns' fireplace rotates, the items on the top should have fallen off, but they didn't. They also disappear/reappear between frames. (00:16:10)
Other mistake: When we first see Nelson's Roadkill 2000, Nelson is moving backwards, though we see his legs as moving forward. (00:13:25)
Other mistake: How can Sideshow Bob make the "I H8 BART" licence plate if there are no number keys on the keyboard? (00:04:45)
Other mistake: Near the beginning of the episode when Selma and Sideshow Bob arrive at the Simpsons' house, Bart and Lisa scream and hide behind Marge. Selma says "What the - ?" but the DVD subtitles say that Marge says it. It is shown "MARGE: What the - ?". (00:02:30)
Simpsons Bible Stories - S10-E18
Other mistake: Rev. Lovejoy is reading Genesis, the first book of the bible, but he is a good way into the book. Surely it would be at The Front?
Other mistake: When the pupils are doing the test at school, you hear Miss Hoover say a question with three possible answers; but 1) There are 5 possible answers on the test when we see Lisa doing it, and 2) Miss Hoover says the 60th question, but Lisa looks to be nowhere near the 60th question.
Other mistake: At the end when Bart and Homer are singing "twinkle twinkle little star" Bart's tongue is green.
Other mistake: When Homer is crossing the rickety bridge in the snow plow there is no snow on the planks even though he is in a blizzard and the storm couldn't have just started because the path he just came from was covered in snow. (00:18:55)
Homer vs. Patty and Selma - S6-E17
Other mistake: When Homer burns a dollar bill, he turns his cigar around 180 degrees. If you look carefully, the smoke soon comes from the different side than it did earlier.
The Secret War of Lisa Simpson - S8-E25
Other mistake: When Lisa looks down from the platform before crossing the obstacle course, you can see her feet, but not the platform she stands on. (00:19:04)
Other mistake: When The Town is singing the Christmas carol you can see Sideshow Bob, who was arrested and jailed in series 1. We know he hasn't been released, as that's a plot point over the show. (00:18:10)
Lisa's Pony - S3-E8
Other mistake: When Lisa rings Homer to tell him that she loves him, the shot of her talking is re-used from "Bart's Dog Gets an F." We can tell this because her cheeks inexplicably appear puffed up (in "Bart's Dog Gets an F" she had mumps).
Other mistake: In this episode, Smithers' skin is brown, however in future episodes, his skin is yellow. (00:05:00)
The Bart Wants What It Wants - S13-E11
Other mistake: Ned Flanders wins the $100 bill, but on the side it says $50.
Other mistake: When Homer is being interviewed while feeding baby Lisa, there's a picture of 8 year old Lisa in the background.
Other mistake: In the DVD booklet, two errors are made for this episode. The booklet says Homer accuses Bart of ruining Thanksgiving and Bart was jealous of Lisa's centre piece. These are both incorrect: First, it wasn't Homer who accused Bart of ruining Thanksgiving, it was Marge who accused Bart of ruining Thanksgiving and second, at no point throughout the episode was Bart ever jealous of Lisa's centre piece.
Krusty Gets Kancelled - S4-E22
Other mistake: When the Red Hot Chili Peppers are performing on Krusty's TV special, bassist Flea is playing a standard electric guitar.
Other mistake: During the Planet of the Apes musical final number, as the chorus line dances on stage from left to center with the Statue of Liberty in the background; however, parts of the Statue (the pink background between arm and book) cut off the dancer's head as if it is in the foreground. (00:12:19)
Suggested correction: Maybe he was allowed to participate due to good behavior. That's a possibility.
Rubbish. He is denied parole numerous times and shown to be a high risk prisoner.
Ssiscool ★
Good behavior or not, a prison wouldn't furlough an inmate just so they could participate in a snow day.
Phaneron ★
I'm not sure if it's been discussed here or listed as a mistake. Part of the problem with "The Simpsons" and the Sideshow Bob character is that time both moves forward and doesn't move. In "A Brother From Another Series," Krusty visits the prison and tells Bob he hasn't seen him in years because Bob had been in prison all those years for his crimes. Yet Bart and Lisa are still the same age and in the same grade. Bob is also let out of prison on a work-release program in the episode.
Bishop73